scholarly journals A ternary composite oxides S2O82−/ZrO2–TiO2–SiO2 as an efficient solid super acid catalyst for depolymerization of lignin

RSC Advances ◽  
2017 ◽  
Vol 7 (79) ◽  
pp. 50027-50034 ◽  
Author(s):  
Huizhen Wang ◽  
Wenzhi Li ◽  
Jindong Wang ◽  
Hou-min Chang ◽  
Hasan Jameel ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Acid Catalyst ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Ternary Composite ◽  
Composite Oxides ◽  
Brönsted Acid ◽  
Super Acid ◽  
Lignin Depolymerization

The solid, super, acid catalyst S2O82−/ZrO2–TiO2–SiO2, which has both a strong Brønsted acid and Lewis acid, was prepared and applied in lignin depolymerization.

scholarly journals Tartaric Acid–Zinc Nitrate as an Efficient Brønsted Acid-Assisted Lewis Acid Catalyst for the Mannich Reaction

2018 ◽  
Vol 42 (9) ◽  
pp. 463-466 ◽  
Author(s):  
Hao Dong ◽  
Qing Liu ◽  
Yuanyu Tian ◽  
Yingyun Qiao
Keyword(s):  
Tartaric Acid ◽  
Lewis Acid ◽  
Mannich Reaction ◽  
Reaction Times ◽  
Acid Catalyst ◽  
Zinc Nitrate ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
One Pot ◽  
Brönsted Acid

Tartaric acid–zinc nitrate has been found to be an efficient Brønsted acid-assisted Lewis acid catalytic system for the facile synthesis of β-amino carbonyl compounds through the one-pot Mannich reaction of aldehydes, aromatic amines and ketones in ethanol at room temperature. Remarkable enhancement of reactivity by tartaric acid (Brønsted acid) was observed in these reactions in the presence of anhydrous zinc nitrate (Lewis acid), due to coordination of the tartaric acid ligand to zinc ions increasing the acidity of the system. This procedure shows some advantages such as mild reaction conditions, short reaction times and high yields.

scholarly journals Tailoring Lewis/Brønsted acid properties of MOF nodes via hydrothermal and solvothermal synthesis: simple approach with exceptional catalytic implications

2021 ◽  
Author(s):  
Sergio Rojas-Buzo ◽  
Benjamin Bohigues ◽  
Christian W. Lopes ◽  
Débora M. Meira ◽  
Mercedes Boronat ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Active Site ◽  
Solvothermal Synthesis ◽  
Simple Approach ◽  
Organic Reactions ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Acid Properties ◽  
Brönsted Acid

The Brønsted/Lewis acid properties of Hf-MOF-808 can be tuned by simply controlling the solvent employed in its synthesis, with direct catalytic implications on the activity and selectivity of organic reactions sensitive to the active site nature.

Study on the removal and depolymerization of lignin from corn stover through the synergistic effect of Brønsted acid, Lewis acid and hydrogenation sites

Fuel ◽  
2021 ◽  
Vol 305 ◽  
pp. 121509
Author(s):  
Baikai Zhang ◽  
Wenzhi Li ◽  
Tingwei Zhang ◽  
Xu Li ◽  
Ajibola T. Ogunbiyi ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Corn Stover ◽  
Lewis Acid ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Brönsted Acid

Critical role of Bronsted acid in Lewis-acid-catalyzed synthesis of Amadori and Heyns compounds of β-amino acids

2021 ◽  
pp. 1-11
Author(s):  
Debasree Chanda ◽  
Gangothri M. Venkataswamy ◽  
Lagamawwa V. Hipparagi ◽  
Nanishankar V. Harohally
Keyword(s):  
Amino Acids ◽  
Lewis Acid ◽  
Critical Role ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Brönsted Acid ◽  
Acid Catalyzed

scholarly journals Reaction Kinetics of Levulinic Acid Synthesis from Glucose Using Bronsted Acid Catalyst

2021 ◽  
Author(s):  
Meutia Ermina Toif ◽  
Muslikhin Hidayat ◽  
Rochmadi Rochmadi ◽  
Arief Budiman
Keyword(s):  
Reaction Kinetics ◽  
Glucose Concentration ◽  
Levulinic Acid ◽  
Acid Catalyst ◽  
Operating Conditions ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Initial Glucose Concentration ◽  
Brönsted Acid ◽  
Kinetics Of

Abstract Glucose is the primary derivative of lignocellulosic biomass, which is abundantly available. Glucose has excellent potential to be converted into valuable compounds such as ethanol, sorbitol, gluconic acid, and levulinic acid (LA). Levulinic acid is a very promising green platform chemical. It is composed of two functional groups, ketone and carboxylate groups which can act as highly reactive electrophiles for nucleophilic attack so it has extensive applications, including fuel additives, raw materials for the pharmaceutical industry, and cosmetics. The reaction kinetics of LA synthesis from glucose using hydrochloric acid catalyst (bronsted acid) were studied in a wide range of operating conditions, i.e., temperature of 140-180 oC, catalyst concentration of 0.5-1.5 M, and initial glucose concentration of 0.1-0.5 M. The highest LA yield is 48.34 %wt at 0.1 M initial glucose concentration, 1 M HCl, and temperature of 180 oC. The experimental results show that the bronsted acid catalyst's reaction pathway consists of glucose decomposition to levoglucosan (LG), conversion of LG to 5-hydroxymethylfurfural (HMF), and rehydration of HMF to LA. The experimental data yields a good fitting by assuming a first-order reaction model.

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